Rotary valve

ABSTRACT

The invention to which this application relates is the provision of an engine or pump which operates in an improved manner. The engine or pump is provided with a cylinder for selective connection with an inlet to allow the fuel and air mixture to be introduced and an exhaust to allow the removal of gases following combustion in the chamber of the cylinder. The connection of the combustion chamber with the inlet and exhaust is selectively controlled by a rotary valve arrangement. The control of the valve arrangement allows the efficient operation of the cylinder and in turn each of the other cylinders of the engine or pump and thereby improve efficiency in the power and drive obtained from the engine or pump.

[0001] The invention to which this application relates is to provide an improvement to the operation of pumps and engines and particularly, although not necessarily exclusively, to the provision and operation of the cylinder valves of the engine or pump in such a manner as to render the same efficient and more economical than conventional engines or pumps, hereinafter referred to as the general term of engines.

[0002] The provision of the combustion engine is readily accepted as a significant breakthrough in engine development but, since then, and while there have been numerous developments, said developments tend to have been relatively slight, with the general operating characteristics of engines remaining constant. One of the areas which has remained largely constant is the operation of the valve for the control of the cylinder and the introduction of the gas fuel mixture into the combustion chamber to act upon the linearly moving piston when the mixture is ignited. The conventional valve arrangement is relatively inefficient and the range of compression ratios which can be achieved relatively limited. In many ways therefore the use of the conventional valve arrangement has meant that the efficiency and performance of the cylinders in the engines have been retarded by the valve arrangement in particular.

[0003] The aim of the present invention is to provide a valve arrangement which allows the engine cylinders to continue to work in the required manner but also to provide an engine which operates in a more efficient manner than is currently achievable.

[0004] In a first aspect of the invention there is provided an engine or pump, said engine or pump including one or a plurality of cylinders, each of said cylinders including a piston arrangement linearly movable therealong and a combustion chamber for the ignition of a gas fuel mixture introduced into the chamber through an inlet and exhaust gases from the combustion exiting via an exhaust and wherein the opening and closing of the inlet and exhaust are controlled by a valve, said valve having a valve head defining a passage, said passage selectively connecting the combustion chamber with the inlet and exhaust by rotation of the valve.

[0005] In one embodiment the valve rotates in a reciprocal manner with rotation in a first direction to allow connection with the inlet and the combustion chamber, followed, a definable time thereafter by rotation in a second direction to connect the combustion chamber with the exhaust and the movement is repeated thereafter in sequence. In this embodiment, which is preferred, the reciprocal movement described gives the effect of the valve moving in a “rocking” fashion to allow the selective connection between the inlet and the exhaust and the combustion chamber. The provision of this rocking movement minimises the movement of the valve that is required between the two positions, thereby rendering the apparatus more efficient. It also means that there is clear differential between the inlet and exhaust connection which means that the efficiency of the engine is not affected by the possibility of, for example exhaust gases moving in one direction conflicting with the required gas flow of the inlet in the reverse direction, especially if, as preferred, the valve has at least two passages, a first for connection of the inlet and the combustion chamber and a second for connection with the combustion chamber and exhaust.

[0006] Typically there is a considerable period of operation in any cycle where it is desired that the passages are closed to both the inlet and exhaust and the passages are formed such that when the valve is in a rest position both passages are sealed from the combustion chamber, exhaust and inlet of the cylinder.

[0007] In an alternative embodiment the valve is provided with a single passage, said passage rotatable as part of the valve between a first position connecting the inlet to the combustion chamber and a second position to connect the combustion chamber with the exhaust.

[0008] Simultaneously with the control of the movement of the valve, the piston in each cylinder follows a conventional path, whether it be two stroke, four stroke or as required and so the operation of the engine is maintained, but in a more efficient manner due to the more efficient control of the valve arrangement as defined in this invention.

[0009] Typically, during the compression of the gas fuel mixture in the combustion chamber by the piston, the rotary valve passages are blanked off by the cylinder head and the gas fuel mixture is sealed in the combustion chamber.

[0010] In whichever embodiment, the rotation, whether reciprocal or otherwise, of the rotary valve head is driven by the crankshaft of the engine. The drive arrangement between the crankshaft and the valve can be provided to provide a controlled speed of rotation and, indeed commencement of rotation so that the movement of the valve is sequentially controlled with respect to the movement of the piston. In another embodiment the rotation of the valve can be electronically controlled and driven.

[0011] Typically this arrangement is repeated for each cylinder of the engine.

[0012] In one embodiment the face of the piston in the cylinder is shaped so as to at least partially follow the shape of the outer surface of the valve which is exposed in the cylinder.

[0013] Specific embodiments of the invention are now described with reference to the accompanying drawings wherein;

[0014]FIG. 1 illustrates the components of a cylinder arrangement in accordance with one embodiment of the invention;

[0015]FIG. 2 illustrates the cylinder arrangement of FIG. 1 in use during a cycle of a four stroke internal combustion engine; and

[0016]FIG. 3 illustrates a further embodiment of a four stroke internal combustion engine in accordance with the invention.

[0017] Referring firstly to FIG. 1 there is illustrated a cylinder arrangement which can be provided a number of times in an internal combustion engine. Each cylinder arrangement comprises the cylinder 2 which defines a combustion chamber 4, a piston 6 driven by a crankshaft 8 and connecting rod 10. The cylinder head includes an inlet 12 and exhaust 14, each of which are selectively connectable with the cylinder via a valve 16 with a valve head which , in accordance with this embodiment of the invention, includes one passage 18 provided therein.

[0018] The operation of the cylinder is well known and generally, one cycle involves the introduction of an air fuel mixture, fuel being injected via injector 20 via the inlet 12 into the combustion chamber. The inlet is then closed, the mixture compressed by the movement of the piston 6, and the mixture is ignited via a spark from the spark plug 22. The ignition causes the piston to be driven down and in turn drives the engine. The exhaust gases from the combustion exit the chamber 4 via the exhaust 14. This process is repeated for each cycle.

[0019]FIGS. 2a-h now illustrate the process of one cycle using the current invention in one embodiment. In contrast to conventional control valves for the introduction of the fuel air mixture and the exhaust of gases, only one valve arrangement is required. The valve arrangement has a head 24 with a passage 18 defined therein. The passage passes through the head with exits 26,28 at each end. The drawing on the left of the FIG. 2 illustrates the position of the components at the start of the cycle and it will be seen that both passage exits 26, 28 are blocked by the cylinder walls. However the valve is rotatable, typically driven by the crank shaft 8, and as the cycle commences the piston 6 moves down and the valve rotates so that the passage exit 26 matches the inlet and the exit 28 matches with an opening into the combustion chamber so that the fuel air mixture 30 enters the chamber 4 for a given time.

[0020] The valve is then rotated again to close the exits 26,28 for a period of time as indicated as the piston rises to compress the fuel air mixture as indicated by arrow 32. When combustion occurs the piston is forced down as indicated by arrow 34 and continued rotation of the valve eventually brings the passage 18 into the position shown at the right of the FIG. 2 in which the exit 26 is open to the combustion chamber 4 and the exit 28 is open to the exhaust 14 to allow the exhaust gases to escape from the combustion chamber. The cycle can then be repeated.

[0021]FIG. 3a-h illustrates a further embodiment of the invention which is in some ways preferred. This Figure illustrates the same cycle and the same components as FIG. 2 with the exception that the valve head 24 includes two passages 40,42 rather than one. In this case the valve head is rotated but in a reciprocal or rocking manner so that firstly, the valve is rotated in the direction 39 so that passage 42 can be connected with the inlet 12 and combustion chamber 4 as indicated in FIG. 3b and then moved back to a sealed closed condition of FIGS. 3c-g during the combustion cycle with movement of the piston 6 in a similar manner to that of FIG. 2, whereupon, subsequent movement of the valve in the reverse direction, indicated by arrow 41 allows the passage 40 to connect with the exhaust 14 as shown in FIG. 3h and allow exhaust gases to leave the chamber.

[0022] Thus in this case the rotational movement of the valve head is considerably reduced with comparison to the first embodiment and so, mechanically, represents a simpler and more efficient mechanism while producing the same effects. This embodiment also means that there is no turbulence or counterflow problems with gases moving in both directions. As the two passages are separate there can be possibility of counterflow gases being present which in turn allows improvement in the efficiency of operation of the assembly

[0023] In which ever embodiment, the present invention allows improved and increased passage for exhaust gases and inlet fuel/air mixtures and therefore improves the volumetric efficiency of the engine as a whole without unduly affecting the size of the engine cylinder.

[0024] Furthermore the compression ratios which can be achieved are not limited as with previous engines and so specific power output increases can be achieved if required along with a considerable reduction in the components which are required thereby reducing the cost of the engine production. 

1. An engine or pump, said engine or pump including one or a plurality of cylinders, each of said cylinders including a piston arrangement linearly movable therealong and a combustion chamber for the ignition of a gas fuel mixture introduced into the chamber through an inlet and exhaust gases from the combustion exiting via an exhaust and wherein the opening and closing of the inlet and exhaust are controlled by a valve, said valve having a valve head defining a passage, said passage selectively connecting the combustion chamber with the inlet and exhaust by rotation of the valve.
 2. An engine or pump according to claim 1 characterised in that the valve rotates in a reciprocal or rocking manner with rotation in the first direction to allow connection of the inlet and combustion chamber and rotation in a second direction to allow connection of the combustion chamber with the exhaust.
 3. An engine or pump according to claim 2 wherein there is a set time delay following movement in the first direction and prior to movement of the valve in the second direction.
 4. An engine or pump according to claim 2 wherein the valve has two passages, a first passage for connection of the inlet with the combustion chamber and a second passage for connection of the combustion chamber with the exhaust.
 5. An engine or pump according to claim 1 wherein in one cycle of operation of the valve, the connections to both the inlet and exhaust are closed for a period of time.
 6. An engine or pump according to claim 5 wherein when both inlet and exhaust connections are closed, the valve is in a rest position.
 7. An engine or pump according to claim 1 wherein the valve is provided with a single passage, said passage rotatable as part of the valve to a first position connecting the inlet to the combustion chamber and a second position connecting the combustion chamber with the exhaust.
 8. An engine or pump according to claim 1 wherein, simultaneously with the control of movement of the valve, the piston in each cylinder follows a conventional linear path.
 9. An engine or pump according to claim 8 wherein during the compression of the gas fuel mixture in the combustion chamber by the piston, the valve passages are blanked off by the cylinder head and the gas fuel mixture is sealed in the combustion chamber.
 10. An engine or pump according to claim 1 wherein the rotation of the rotary valve head is driven by the crank shaft of the engine or pump.
 11. An engine or pump according to claim 10 wherein the drive arrangement between the crank shaft and the valve provides a controlled speed of rotation of the valve and controls the commencement and stop of rotation.
 12. An engine or pump according to claim 11 wherein movement of the valve is sequentially controlled with respect to the movement of the piston.
 13. An engine or pump according to claim 1 wherein the rotation of the valve is electronically controlled and driven.
 14. An engine or pump according to claim 1 wherein the arrangement as described for one cylinder is repeated for each of the cylinders of the engine or pump.
 15. An engine or pump according to claim 1 wherein the face of the piston and cylinder are shaped so as to at least partially follow the shape of the outer surface of the valve which is positioned in that cylinder. 